The present invention concerns a multi-layer, substantially polyvinyl chloride and polyolefin-free composite film, in particular furniture film, including at least one carrier layer which has ABS (acrylonitrile butadiene styrene), in particular ABS with admixtures; and/or polystyrene; in particular polystyrene with admixtures and/or high-impact polystyrene, and/or polyester, in particular amorphous polyester copolymer.
When using thermoplastic decorative films in the furniture sector, particularly when high-shine surfaces are involved, high demands are made in terms of scratch resistance, abrasion resistance, chemical resistance, tension tearing resistance and optical values such as shine, long- and short-wave factors as well as surface fine roughness. Environmental awareness is also increasingly advancing into the furniture sector, so that demands are also additionally being made in terms of the material nature of the thermoplastic films. The materials and processes used at the present time do not always satisfy those conditions.
Furniture films of thermoplastic materials are produced for example by laminating/coating a thin scratch-resistant layer on to a pigmented polyvinyl chloride (PVC) carrier film and subsequently applying a primer layer at the rear side. Admittedly, PVC carrier films substantially satisfy all physical and optical requirements of furniture films, but, on the other hand, nowadays they are considered ecologically questionable. A more ecologically advantageous variant was marketed, using a base film of pigmented amorphous polyester copolymer, instead of the pigmented PVC base film, has been marketed. Further alternatives on a polyolefinic carrier basis are described in EP 0 987 102 A2, which discloses a base of polyethylene, a scratch-resistant coating, and also an overlay film of transparent amorphous polyester copolymer. In addition, EP 0 704 482 B1 discloses a plurality of structures in which polyolefins are homogenised with polymers of other chemical classes (styrene copolymers, polymethacrylates) and processed to constitute films for furniture and articles of furniture. EP 0 875 374 A2 describes a product for which a carrier film including polyolefins, ABS (acrylonitrile-butadiene-styrene copolymers), ASA (acrylonitrile-styrene-acrylic ester copolymers), AES (thermoplastic quadrupolymer of acrylonitrile-ethylene-propylene-styrene), PET (polyethylene terephthalate), or an amorphous polyester is laminated with an overlay film of an amorphous polyester. Japanese specification No 08311301 A describes an ABS film to which a defined addition of polycaprolactone is added as a processing aid for the calendering process. The ABS film may also contain between 5 and 50 percent by weight of methacrylate raw material.
Co-extruded panels of polymethylmethacrylate (PMMA) and ABS are also known as high-shine film materials. Furniture films are produced in that case by co-extrusion with a wide-slot nozzle. An alternative form of processing involves thermoshaping of the films and subsequently adhering the film to wood fibre panels. A further alternative form of processing involves glueing on to flat surfaces and hot edging. In general terms, thermoplastic, high-shine furniture films and mats are processed by pressing, laminating, or shaping on wood or foam cores. In order to be able to process the films on existing machines, the films must satisfy defined technical conditions. In particular, the films must have, interalia, good thermoshapability at low temperatures (100° C.) and a corresponding processing window of between 90° and 120° C. In addition, the films should have improved surface properties (shine, long wave, short wave, UV (ultraviolet light) resistance, scratch resistance, chemical resistance) as well as good adhesion to wood materials, pieces of wood, or foam cores. Those demands are only partially or not at all fulfilled by the PVC-free films in the art, which are desired from an ecological point of view.